National Outcomes in Acute Aortic Dissection: Influence of Surgeon and Institutional Volume on Operative Mortality

Abstract

Despite clinical and technical advances, acute aortic dissection carries high operative mortality. This study was designed to establish whether this is influenced by institution and surgeon volume. Outcomes of 5,184 patients (mean age, 60.3 years; 65.9% male) diagnosed with acute aortic dissection from the Nationwide Inpatient Sample from 2003 to 2008 were analyzed with risk-adjustment for preoperative comorbidity using multivariate logistic regression analysis. Overall operative mortality was 21.6%, with similar preoperative patient risk profile across institutions and individual surgeons. A strong inverse relationship was observed between operative mortality and both institution and surgeon volume: surgeons who averaged less than 1 aortic dissection repair annually had a mean operative mortality of 27.5%, compared with 17.0% for those averaging 5 or more annually (odds ratio, 1.78; 95% confidence interval, 1.39 to 2.29; p < 0.001). This was similar to therelationship seen between institution volume and mortality: operative mortality was 27.4% in institutions performing 3 or fewer acute aortic dissections a year, compared with 16.4% in those performing more than 13 annually (p<0.001). Nationally, operative mortality decreased steadily from 23% in 1998-2000 to 19% in 2005-2008, with no significant decrease in patient risk profile. Patients undergoing emergency repair of acute aortic dissection by lower-volume surgeons and centers have approximately double the risk-adjusted mortality of patients undergoing repair by the highest volume care providers. Routine involvement, whenever feasible, of teams experienced in acute aortic dissection repair may be a strategy to reduce operative mortality and major morbidity.